An image exposure apparatus is provided and includes: an optical unit that emits light to form an exposure image on a photosensitive material; a casing that houses the optical unit and that has an image exposure window through which the light is allowed to pass for forming the exposure image; a transparent dustproof member at the image exposure window; and a shutter member switched between a shield position for covering a region above the dustproof member, which serves as a passage region of a cleaning member for cleaning a surface of the dustproof member, and an open position for allowing the light to pass through the dustproof member to form an exposure image on a surface of the photosensitive material. When the shutter member is located at the shield position, at least a part of the shutter member goes into the passage region of the cleaning member.